As used herein, the term ‘scab’ refers to a hardened or solidified crust produced by a cutaneous sore, wound, ulcer, or pustule. For instance, a scab or scab portion principally refers to blood components that have been released from a patient and, subsequently, hardened or solidified into a crust-like deposit on or proximate the patient's skin.
It is commonly desired to enable sub-scab access, that is, access below the scab or to the area below a portion of the scab. In a number of medical procedures, a single site or access point is used and re-used for access to a patient's vascular or arterio-venous system. One example of such procedure is for extracorporeal blood treatment such as hemodialysis. Alternatively, there are many times where re-use of a particular access site is desired, such as for repeated drawing of blood, blood transfusions, provision of medicaments, or other blood treatment procedures.
During such described procedure, a particular access site is located. It is noted that were a plurality of proximate sites used, such can damage or destroy parts of the vascular system, often referred to as a section of the vascular system “collapsing.” Access is gained percutaneously via a needle, for instance, so that blood in the vascular system can be withdrawn and/or so that fluid (including blood, such as during hemodialysis) can be returned or added to the patient's bloodstream.
When the needle is removed, it is common for the access site to be closed by application of pressure. Closing of the vascular access site is necessary because a patient's blood pressure is higher than that of ambient pressure, and, regardless of the use of the site to infuse fluid or to draw fluid, the vascular pressure will force blood out of the vascular access site.
In any event, the vascular access site deposits blood fluid and/or other fluid at the access site, fluid which forms a scab when contacted by air. Principally, the scab may comprise blood platelets. As a coagulation mechanism, the platelets recognize the formation of the access site, such as by a needle, as an injury. The platelets respond to this by adhering to each other and to the edges of the injury, such as the opening formed in the vascular system, as well as to the patient's flesh between the vascular system access site and the surface of the skin. The platelets then coagulate, which includes retracting or shrinking across the injury to stop the loss of blood and to form a barrier to infection. Finally, in the presence of air (as opposed to a blood clot), the platelets harden to form the scab.
In order to access the vascular site a subsequent time, the scab must be overcome. Obviously, a medical technician could attempt to bypass the scab, working along an edge thereof; however, this is unlikely to be very effective, yet is nonetheless likely to be tedious. Generally, a medical technician or patient, as in home hemodialysis, simply removes, in crude fashion, the scab from the access site. For instance, the technician may use a sterile needle tip or sterile tweezers to pick at the edge of the scab to dislodge and lift the scab from the flesh surrounding the access site.
It should be emphasized that the access site is a direct portal into the patient's bloodstream. Use of a non-sterile device or second use of a sterile device for removing the scab is virtually tantamount to injecting bacteria into a patient's bloodstream. If an access needle tip is used, the scab is certainly not sterile, and subsequent insertion of the needle tip into the patient's vascular system after picking at the scab is similarly injecting potential pathogens into a patient's bloodstream. The needle may be dulled or deformed by use as a picking device, making the insertion more painful or damaging to vascular tissue. Finally, particulate matter, either non-sterile scab material or non-sterile skin material, may be carried with the needle tip into the bloodstream.
PCT application WO2008/005441, assigned to JMS Company, LTD (“the JMS application”) discloses a “Needle Cover with Site Preparation Tip.” While a needle and needle set typically have a cover to protect the needle (both for sterility and to maintain a sharp edge for non-blunt needles), the JMS application teaches a “needle cover shaped for removing scabs” for use in assisting with removal of the scab. It further teaches to leave the needle cover in place on the needle set during scab removal. Because a typical needle set for constant site cannulation is a minimum six inches long, this leaves the user with the choice either of manipulating the entire needle set (including the long, tail-like associated tubing and connectors) in order to use the “tip” and trying to keep the friction fit cover from disconnecting from the needle set, or of purposefully removing the needle cover from the needle set (in order to have a more finely controllable site preparation tip) which breaks sterility of the needle and renders it unsafe for cannulation into the patient.
The JMS application describes the needle cover including tip being formed of polyurethane, polyethylene, polypropylene, and the like, each of which is a relatively soft material. The softness of the material is necessary so that the cover can be releasably secured, frictionally, with the needle hub. The result is that the tip itself is formed of a soft material. As the entire product (i.e., needle set with cover and tip) would be packaged in a paper/plastic wrapper, the soft tip is susceptible to being blunted or damaged during packaging, shipping, storage, and other handling and generally not ideal for trying to lift out a hardened scab.
Additionally, sterility of the tip is broken when the outer wrapper of the needle set is opened. In a typical procedure, the needle set would be removed from its package well before removal of the scab, and would then be placed proximate the patient's arm on an unsterile field along with the many other items needed for the cannulation procedure. The needle cover maintains sterility of the cannulating needle while the the access site is prepared, which is after, for instance, an antiseptic cleansing of the area. In other words, the clinician must make a choice between removing the needle set of the JMS application from the package and leaving it exposed while cleaning the access site, or cleaning the site and then handling the non-sterile exterior wrapping of the needle set to open the needle set during which time the access site is exposed. Notably, this fact is resonated by the JMS application stating that the cover should be removed from the needle, and the needle inserted “without delay,” yet the JMS application fails to appreciate that the preparation tip itself faces similar risks, since it is used to dig around the constant site opening to the patient's circulatory system. In fact, while the JMS application states the order of steps may be modified, there are constrictions on how they may be done, at least such that choices must be made between what sterility is maintained and what is foregone.
Accordingly, there has been a need for an improved device to enable the removal or dislodgement of a scab to access a vascular site, the device preferably being sterile.